The only maintenance I do myself is day-to-day stuff - cleaning the drivetrain once in a while, repairing flats/replacing tires, swapping brake pads (when swapping wheels), stuff like that. I helped in putting my Casati together the first time, and assembling and disassembling it when I took it on vacation, but I've never been mechanically inclined, and am clumsy when it comes to handiwork. I did manage to figure out how to get the brake lever re-attached to the bars of my fixed gear bike when it slipped off the other day. Although I do believe it's important to understand how the machines we operate work, and I am interested, I could never be a reliable mechanic. I have enjoyed trusting my cars, motorcycles and bikes to those with developed expertise and skill - they always turn out much nicer than I could have made them.